PM2.5 Airborne Particulates Near Frac Sand Operations
Kristen Walters,
Advisor: Dr. Crispin Pierce, University of Wisconsin-Eau Claire.
 Environmental Public Health, University of Wisconsin-Eau Claire 
Introduction
Results
o Hydraulic fracturing, or fracking, is a popular method for
extracting natural gas from shale deposits below the
earth’s crust. (7,8,9)
o The geology of Wisconsin has optimal sand deposits for
the process. (7,9)
o The number of frac sand mines in WI has greatly
increased in recent years. (see figure 7)
o Over 140 permitted frac sand mines & processing
plants are located in Wisconsin. (See figure 1) (3,7)
o Frac sand is used during extraction as a proppant to hold
open the fractured shale during removal of natural gas (3).
o Crystalline silica & other small particulate matter have
been shown to be a concern for health. (1,4,5)
o “Freshly-fractured” silica appears to be 2 to 5 times more
reactive with animal lung tissue than “weathered” silica,
though weathering occurs within several days & with
exposure to water. (5)
o Numerous reports of dust accumulation at people’s homes
& businesses have led to an increased need to
investigating air quality surrounding those frac sand
facilities. (3)
o PM2.5 levels during the five sampling events ranged from
5.82–50.8 µg/m3. (see figure 2)
o Monitoring of PM2.5 conducted in a controlled environment
with multiple devices showed results of between 5-17.74
µg/m3. (see figure 3)
o Monitors from the Minnesota Pollution Control Agency
(MPCA) in Winona, MN showed similar results to our
data. (see figure 4 & 5)
o Levels of PM2.5 affected by precipitation, wind speed, &
degree of frac sand facility activity.
Figure 7: The increase in frac sand production in WI
from 1975-2011. (6)
Average PM2.5 Concentration in HSS 218 Lab
Conclusions & Recommendations
20
17.74
18
PM2.5 Concentration ug/m3
16
14
o Elevated levels of PM2.5 during active frac sand mining &
processing operations. (see figure 3)
13.7
14
12
10
o consistent with our findings using a TSI DustTrak™ 8520
aerosol monitor (a battery-operated, portable light-scattering
laser photometer) used extensively in particulate
measurement.
8
6
5
4
2
0
Air Sampling Instruments
DustTrak II
DustTrak I
SKC DPS
Dichot Sampler
Figure 3: A calculated average of PM2.5 concentrations were taken in a controlled environment in HSS 218 Research Lab
at UW- Eau Claire. Standard deviations (S.D.) were not used for instruments DustTrak I and II. DPS displayed a S.D. of
+/- 3.74 and Dichot displayed a S.D. of +/- 1.23. (3)
60
50
Concentration (ug/m3)
o Future research with federal-reference Andersen
dichotomous sampler & direct reading instruments
o Provide testing options for local health departments using less
expensive instruments.
Measured 24-Hour PM2.5 Levels
Purpose
Figure 6: Photo of Superior Silica Sand mine
in Bloomer, WI on November 5, 2011. (2)
US EPA annual
PM2.5 standard
of 12 µg/m3
40
30
o Health departments & elected officials face questions
about health risks associated with frac sand mining.
o More research needed to make informed decisions regarding
policy making & when creating regulations.
20
10
Figure 1: WI map of frac sand site. (6)
0
Bridge Creek
o Quantitatively characterize the PM2.5 & PM10 particulate
concentrations in the air around frac sand facilities &
evaluate the risk as compared to national standards.
Arcadia
New Auburn
New Auburn
Winona
Figure 2: Locations & Measured PM2.5 concentrations near frac sand mining & processing sites. Results with S.D. were
calculated as: Bridge Creek 13.8+/- 6.79 µg/m3,Arcadia 13.8+/- 6.79 µg/m3, New Auburn 50.8+/-9.48 µg/m3, New Auburn
23.6+/-3.16 µg/m3, Winona 19.6+/-1.74 µg/m3. (3)
Figure 8: Jennifer Scmidtz, Jon Jilek, Alayna
Spangler, & Kristen Walters; part of the
current research team testing our new
Andersen dichotomous samplers & the DPS.
Site 1 Winona Hourly PM2.5 Samples
12
Concentration (ug/m3)
o 24-Hour ambient air samples were collected with an SKC
DPS sampler using the PM2.5 sampling head.
o Sampling was conducted near mining sites using the
DPS, TSI DustTrak™ I 8520, and the TSI DustTrak™ II
8530 and compared to local monitors, if available.
o Sampling was conducted on the top of the research
building and in the lab using the Andersen dichotomous
sampler, DPS, TSI DustTrak™ I 8520, and the TSI
DustTrak™ II 8530.
o PVC filters were weighed pre- & post-exposure 6 times
using a Mettler Toledo AT261 DeltaRange® balance for
the DPS and the Andersen sampler.
o The PM2.5 sample inlet was mounted 2 m high, away from
buildings & trees, as described in EPA sampling protocol.
o Temperature, humidity, wind speed, wind direction, &
GPS coordinates were also recorded at each site.
8
US EPA annual
PM2.5 standard
of 12 µg/m3
6
4
2
0
Air Sampling Instruments
MPCA
DustTrak I
DustTrak II
Figure 4: A calculated average of PM2.5 concentrations were taken near an active frac sand site in Winona, MN. Data from
the DustTrack I and DustTrack II compared to data from the Minnesota Pollution Control Agency. monitor located in
Winona, MN (MPCA). MPCA reported 5 µg/m3, DustTrack I displayed 9.8±0.84 µg/m3, DustTrack II displayed 4.6±0.55. (3)
Site 3 Winona 22-Hour PM2.5 Sample
US EPA annual
PM2.5 standard
of 12 µg/m3
20
Concentration (ug/m3)
Methods
10
15
10
References
1. Health effects of occupational exposure to respirable crystalline silica. (April 2002). Centers for Disease Control and
Prevention. Retrieved from http://www.cdc.gov/niosh/docs/2002-129/
2. Kenosian, M. (2014) Photo Board, University of Wisconsin-Eau Claire Environmental Public health. Retrieved from
http://www.uwec.edu/Watershed/enph/silica/PhotoGallery.htm
3. Pierce, C. (April 2014). PM2.5 Airborne Particulates near Frac Sand Operations. [Word Document].
4. Pope, C.A., Burnett, R.T., Thun, M.J., Calle, E.E., Krewski, D., Ito, K., & Thurston, G.D. (2002). Lung cancer,
cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. The Journal of the American
Medical Association, 287, 1132-1141. doi:10.1001/jama.287.9.1132.
5. Vallyathan, V., Castranova, V., Pack, D., Leonard, S., Shumaker, J., Hubbs, A.F., Shoemaker, D.A., Ramsey, D.M.,
Pretty, J.R., McLaurin, J.L., et al. (1995). Freshly fractured quartz inhalation leads to enhanced injury and
inflammation. Potential role of freeradicals. American Journal of Respiratory and Critical Care Medicine, 152(3), 10039.
6. Wisconsin Center for Investigative Journalism. (2013). Frac sand mines and plants, October 2013 update [Data file].
Retrieved from http://www.wisconsinwatch.org/wi-frac-sand/
7. Wisconsin Department of Natural Resources. (2011). Report to the Natural Resources Board: Silica Study, August
2011, AM-407. Retrieved from http://dnr.wi.gov/files/pdf/pubs/am/am407.pdf.
8. Wisconsin Department of Natural Resources. (2012). Silica sand mining in Wisconsin. Retrieved from
http://dnr.wi.gov/topic/Mines/documents/SilicaSandMiningFinal.pdf
9. Wisconsin Geological and Natural History Survey, University of Wisconsin–Extension. (2013). Frac sand in Wisconsin.
Retrieved from http://wisconsingeologicalsurvey.org/pdfs/frac-sand-factsheet.pdf
Acknowledgments
5
0
MPCA
DPS Filter
Figure 5: A calculated average of PM2.5 concentrations were taken near an active frac sand site in Winona, MN. Data from
the DPS compared to data from the Minnesota Pollution Control Agency monitor located in Winona, MN (MPCA).The
MPCA reported 13.4±4.0 µg/m3 . The DPS displayed 19.7±1.7 µg/m3.(3)
Thank you to the UW-Eau Claire Office of Research & Sponsored
Programs for funding this project & the office of Learning & Technology
Services for printing this poster. Also, the University of WisconsinStout, the University of Iowa-Environmental Health Sciences and
Research Center, & RJ Lee Group, our partners in this research.